Study On Mixing Mechanism And Experiment Of High Distribution Meshing Rotor For Rubber Final Mixing

The rubber mixing process is a key link in the whole process of rubber processing,which has a crucial decisive influence on the quality of rubber products.The mixing process is generally divided into master mixing and final mixing.Due to the different division of labor,functions and purposes between final mixing and master mixing,the mixing equipment,rotor configuration,and process conditions used are also quite different.Powder sulfur and volatile accelerators,etc.,have strict requirements on the mixing temperature,and the temperature of the rubber compound must be strictly controlled during the final mixing process;at the same time,because the proportion of added sulfur and accelerators is small,distributed mixing is particularly important.At present,the industrialized rubber final mixing process production system is mainly composed of open mixers and internal mixers.The internal mixer is the most efficient and most widely used final mixing equipment at this stage.Therefore,it has become one of the important research topics in the industry to study the compound rotor with high distribution and slow temperature rise in the internal mixer suitable for the final rubber mixing to improve the uniformity of the mixed rubber.This research group has developed a compound rotor with high distribution and slow temperature rise of the internal mixer suitable for the rubber final mixing process,and developed the supporting final mixing process technology to realize the specialization of the final mixing of the rubber internal mixer.The main work done in this paper is as follows:(1)The mixing process and mechanism of the high distribution meshing rotor for final rubber mixing were studied.The chemical and physical change process of rubber in the final mixing process of the internal mixer is analyzed,and the local high temperature phenomenon in the final mixing process of the rubber internal mixer is expounded.The micro local precrosslinking mechanism in the final rubber mixing process of the internal mixer was investigated experimentally.(2)The high distribution meshing rotor and experimental platform for final rubber refining were designed and trial produced.Using the three dimensional design software,the parametric design of the highly distributed meshing rotor was carried out,the structural parameters of the rotor were optimized,the optimal design parameters were obtained,the design configuration of the rotor was determined,and trial production was carried out;at the same time,the final rubber compound was assembled.Use a high distribution meshing rotor experimental platform.(3)The EDEM discrete element simulation software is used to simulate the highdistribution meshing type rotor and the ordinary meshing type rotor respectively for the final refining of rubber.The material properties and particle size of the rubber compound and sulfur particles are introduced,and the velocity field distribution of the particles,the particle running trajectories,and the mixing uniformity of the particles during the simulation process of the two rotors are analyzed.It is proved by simulation that the rotor not only has good distribution and mixing performance,but also has the characteristics of slow temperature rise in the final mixing process,and is suitable for rubber final mixing.(4)Developed the final refining technology suitable for the high-distribution meshing rotor used in the final refining of rubber.By setting up an orthogonal experiment,the influence of the changes of the core parameters of each final refining process on the final refining temperature,processing characteristics and physical and mechanical properties was investigated,and the final refining such as the optimal final refining filling factor,rotor speed and final refining time were determined.Core elements of process technology.(5)The mixing characteristics of the high-distribution meshing rotor for rubber final mixing and the final mixing characteristics of three traditional rotor internal mixers and open mixers were experimentally studied.Through the comparative experiment of the high-distribution meshing rotor for rubber final refining and the ordinary meshing rotor,the masterbatch and final mixing characteristics of the highdistribution meshing rotor for rubber final refining are explored,and the highdistribution meshing rotor for rubber final refining is clarified.Advantages in master mixing and final mixing;through the analysis of the discharge temperature,processing characteristics and physical and mechanical properties of the final rubber in the traditional final mixing equipment,it is summarized that different rotor mixers and open mixers have different properties of the final rubber.The influence characteristics guide the traditional final refining process technology and the rotor design for final refining.